02 Nov, 2017

1 commit

  • Many source files in the tree are missing licensing information, which
    makes it harder for compliance tools to determine the correct license.

    By default all files without license information are under the default
    license of the kernel, which is GPL version 2.

    Update the files which contain no license information with the 'GPL-2.0'
    SPDX license identifier. The SPDX identifier is a legally binding
    shorthand, which can be used instead of the full boiler plate text.

    This patch is based on work done by Thomas Gleixner and Kate Stewart and
    Philippe Ombredanne.

    How this work was done:

    Patches were generated and checked against linux-4.14-rc6 for a subset of
    the use cases:
    - file had no licensing information it it.
    - file was a */uapi/* one with no licensing information in it,
    - file was a */uapi/* one with existing licensing information,

    Further patches will be generated in subsequent months to fix up cases
    where non-standard license headers were used, and references to license
    had to be inferred by heuristics based on keywords.

    The analysis to determine which SPDX License Identifier to be applied to
    a file was done in a spreadsheet of side by side results from of the
    output of two independent scanners (ScanCode & Windriver) producing SPDX
    tag:value files created by Philippe Ombredanne. Philippe prepared the
    base worksheet, and did an initial spot review of a few 1000 files.

    The 4.13 kernel was the starting point of the analysis with 60,537 files
    assessed. Kate Stewart did a file by file comparison of the scanner
    results in the spreadsheet to determine which SPDX license identifier(s)
    to be applied to the file. She confirmed any determination that was not
    immediately clear with lawyers working with the Linux Foundation.

    Criteria used to select files for SPDX license identifier tagging was:
    - Files considered eligible had to be source code files.
    - Make and config files were included as candidates if they contained >5
    lines of source
    - File already had some variant of a license header in it (even if
    Reviewed-by: Philippe Ombredanne
    Reviewed-by: Thomas Gleixner
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

27 Mar, 2013

1 commit

  • Inspection of upper layer protocol is considered harmful, especially
    if it is about ARP or other stateful upper layer protocol; driver
    cannot (and should not) have full state of them.

    IPv4 over Firewire module used to inspect ARP (both in sending path
    and in receiving path), and record peer's GUID, max packet size, max
    speed and fifo address. This patch removes such inspection by extending
    our "hardware address" definition to include other information as well:
    max packet size, max speed and fifo. By doing this, The neighbour
    module in networking subsystem can cache them.

    Note: As we have started ignoring sspd and max_rec in ARP/NDP, those
    information will not be used in the driver when sending.

    When a packet is being sent, the IP layer fills our pseudo header with
    the extended "hardware address", including GUID and fifo. The driver
    can look-up node-id (the real but rather volatile low-level address)
    by GUID, and then the module can send the packet to the wire using
    parameters provided in the extendedn hardware address.

    This approach is realistic because IP over IEEE1394 (RFC2734) and IPv6
    over IEEE1394 (RFC3146) share same "hardware address" format
    in their address resolution protocols.

    Here, extended "hardware address" is defined as follows:

    union fwnet_hwaddr {
    u8 u[16];
    struct {
    __be64 uniq_id; /* EUI-64 */
    u8 max_rec; /* max packet size */
    u8 sspd; /* max speed */
    __be16 fifo_hi; /* hi 16bits of FIFO addr */
    __be32 fifo_lo; /* lo 32bits of FIFO addr */
    } __packed uc;
    };

    Note that Hardware address is declared as union, so that we can map full
    IP address into this, when implementing MCAP (Multicast Cannel Allocation
    Protocol) for IPv6, but IP and ARP subsystem do not need to know this
    format in detail.

    One difference between original ARP (RFC826) and 1394 ARP (RFC2734)
    is that 1394 ARP Request/Reply do not contain the target hardware address
    field (aka ar$tha). This difference is handled in the ARP subsystem.

    CC: Stephan Gatzka
    Signed-off-by: YOSHIFUJI Hideaki
    Signed-off-by: David S. Miller

    YOSHIFUJI Hideaki / 吉藤英明